Reinforcing bars are used to lend added strength to concrete structures. The bars are typically arranged in desired spatial relation before forms are set, then concrete is poured into the forms over the previously arranged reinforcing bars. It is a common practice to have the concrete reinforcing bars cross one another in a grid pattern to provide additional reinforcement within the concrete structure in multiple directions. The reinforcing bars must somehow be suspended within the concrete forms in such a manner that the rods will stay in selected positions while concrete is being poured.
The problem of securing patterns of intersecting reinforcing bars has been addressed in the past. The solution offered is the current typical practice to use wire ties, wrapped manually about the bars at their intersections in order to hold the bars in place prior to pouring concrete. While wire ties function adequately, the manual tying process is labor intensive and expensive. Thus a problem remains; how to adequately connect concrete reinforcing bars in a fast and efficient manner.
The above problem has been answered to a degree by the development of plastic clips designed to be snapped over intersecting concrete rods. A U.S. Pat. No. (5,371,991) to Bechtel discloses a "Rebar Clamp Assembly" in which plastic clips are provided to secure ersecting reinforcing rods together.
The Bechtel connectors make use of "C" shaped clips, provided in joined pairs. The clips are either formed integrally or are pivotably connected together with swivels. In either instance, the open "mouths" of the clips in each pair are angularly spaced from one another by an angle of 90.degree.. The internal surfaces of the plastic clip members are smooth and axially uninterrupted.
The angular relation of the "mouths" of the Bechtel clips creates a problem with the structural integrity of the clips themselves. The swivel pins that pivotably join the clips are situated such that one side of each clip is reinforced by the pin, and the remaining side is free to flex. Thus the free sides of the clips are primarily depended upon to flex open to receive reinforcing bars, and can be deformed or break in the process.
The smooth internal bores of the Bechtel clips allow the clips to slide axially along the rods, or to allow the rods to slide along the clips. This can be a serious disadvantage, especially when the clips are to be depended upon to hold a rod in place. By way of example, many reinforced wall constructions require both horizontal and vertical reinforcing rods. The Bechtel clip, attached between a horizontal rod and a vertical rod, may not afford sufficient gripping force to preven the vertical rod from sliding downwardly. Additional support become necessary to hold the vertical rod in place especially as concrete is poured. If sufficient gripping force is provided by spring tension within the clips to hold a rod vertically, then the clips themselves become very difficult to install on the bars.
The present clip arrangement provides a solution to the above problems by enabling uniform gripping of reinforcing rods, with opposed legs of the present clip members flexing substantially equally, and by engaging the rods in such a manner that axial movement of the engaged rods is inhibited. The above and other objects and advantages of the present invention will become further evident from the following detailed description. to support the rods.